Time Travel stories are amazingly common (1, 2), because fiction writers, by virtue of multiple personality, may have personally experienced time travel

Most fiction writers have multiple personality trait, in which alternate personalities may see themselves as being a different age than the person’s actual age.

For example, the regular, host personality sees itself as being the person’s actual age, say 30, but one alternate personality may see itself as being 18 and another as being 5. And the 5-year-old may think that it is still the year in which it originated (when the person was five). So when the person switches to their 5-year-old personality, they will have time-traveled back to the year when the person was five (in subjective reality).

And if the writer, as a child, had read, or been told, historical stories, the reality of those stories may have been adopted as the reality by an alternate personality. Or the child may have come up with its own imaginary world, which is common enough to have been given a name: “paracosm” (3). (Search “paracosm.”)

In short, when fiction writers do time travel stories, they may be writing what they know (by virtue of their multiple personality).

1. https://en.wikipedia.org/wiki/List_of_time_travel_works_of_fiction

2. https://en.wikipedia.org/wiki/Category:Novels_about_time_travel

3. https://en.wikipedia.org/wiki/Paracosm